1. Field of the Invention
The present invention relates to a cyclone reactor that employs self-propagating combustion reaction and in particular to reactor inside which self-propagating combustion takes place to continuously generates high purity metals, alloys, or semiconductor.
2. The Related Arts
Metals or semi-conducting substances of extremely high purity are commonly used in modern industrial product. Taking titanium, zirconium and hafnium, or alloys thereof, which are often used in aerospace industry and biomedical industry, as examples, these metals and their alloys feature low density, high specific strength, excellent corrosion resistance, and good biocompatibility. All these factors make them un-replaceable by other substances. However, the physical or chemical properties of these materials, especially those containing inter-metallic compound of titanium and aluminum, are closely related to their purity. Titanium is traditionally generated by Kroll method since 1967 up to now. The manufacturing process has not changed much since the very beginning. Namely, a batch process in which magnesium is employed to reduce titanium tetrachloride for the generation of titanium sponge. The titanium sponge contains a great amount of impurity of magnesium chloride, which must be removed with vacuum distillation or pickling. During this process, impurity or oxides may be contained in the final product of titanium, leading to poor purity thereof. Additional subsequent processes may be needed for further processing in order to obtain titanium metal with low impurity of oxides. This makes high purity titanium very expensive and as a result limits its applications. Thus, development of novel manufacturing process for high purity titanium metal is now one of the challenges to the industry.
Further taking poly-silicon as an example for semi-conducting substances, this substance is commonly used in the modern electronic and photovoltaic industry. It must be of extremely high purity (>6N) in these applications. Known equipments and methods for manufacturing high purity poly-silicon, such as those described in “Handbook of Semiconductor Technology”, Noyes Publications, Park Ridge, N.J., USA, pp 2-16, which is the so-called Simens process, and is currently the primary process for manufacturing poly-silicon, begins with employing carbon black in an arc furnace to reduce silica sand to obtain metallurgical grade silicon (MG-Si), which is then put into reaction with hydrogen chloride (HCl) to obtain trichlorosilane (SiHCl3). The impurity contained in the so obtained trichlorosilane is removed by repeated low temperature distillation to obtain purified trichlorosilane. The purified trichlorosilane is heated and reduced in a hydrogen atmosphere vacuum furnace to deposit as high purity poly-silicon. Based on the requirement for purity for different applications, one or more additional processes of directional solidification may be further employed to further enhance the purity. Apparently, Simens process is a time- and energy intensive and thus expensive process for manufacturing high purity poly-silicon for semiconductor or photovoltaic industries. Thus, development of equipments and methods for manufacturing high purity poly-silicon with low costs is now one of the challenges to the industry.